Hi All,

FYI, Apache SIS [1], currently Incubating, is working on building an ASLv2 
licensed library comparable to JTS or GeoTools. You'll notice that most of the 
GIS related libs out there are GPL or LGPL (or at least I did), so I decided to 
do something about it.

If anyone else is interested in joining the cause, we'd welcome you over there.

At present, we have code that implements a QuadTree storage and does 
PointRadius and bounding box computations, as well as a REST-ful web service to 
handle spatial location based on those 2 methods. We're close to making an 
0.1-incubating release.

Cheers,
Chris

[1] http://incubator.apache.org/sis/


On 11/8/10 2:40 AM, "Chris Male" <[email protected]> wrote:

Hi,

I'll jump in and give my opinion:

Can you clarify what you mean with "the Sinusoidal projection is broken"?

Inside Spatial Lucene's Cartesian codebase is an implementation of Sinusoidal 
projection.  Grant discovered while working on improving the testing coverage 
of the code that the implementation doesn't actually match the formula 
specified on Wikipedia.  When we tried to change it, many tests broke since the 
overall logic somehow depends on this broken implementation.


Would it be possible to use a LGPL library like the Java Topology Suite (JTS: 
http://www.vividsolutions.com/jts/JTSHome.htm)?

This is something we've talked about using.  I think it would be nice to 
offload some of the geographic-specific from Lucene.  So using another library 
would be good.  At the same time it limits our options for optimizations and 
the like.  I'm certainly looking into it though.

Thanks,
Chris


Neo4j is using JTS for creating a spatial index (code is here: 
https://github.com/neo4j/neo4j-spatial)...

(I've just seen that JTS has some index creation classes, but I'm not at all 
familiar with them)

Christopher


On Mon, Nov 8, 2010 at 1:10 AM, Grant Ingersoll <[email protected]> wrote:

On Nov 6, 2010, at 5:23 PM, Christopher Schmidt wrote:

> Hi Ryan, thx for your answer.
>
> You mean there is room for improvement and volunteers?

We've been looking at replacing it with the Military Grid system.  The primary 
issue with the current is that the Sinusoidal projection is broken which then 
breaks almost all the tests.  I worked on it for a while trying to straighten 
it out, but gave up and now think it is easier to implement clean.  I 
definitely would like to see a tier/grid implementation.


>
> On Friday, November 5, 2010, Ryan McKinley <[email protected]> wrote:
>> Hi Christopher -
>>
>> I do not believe there is any active work on this.  From what I
>> understand, the Tier implementation works OK within some constraints,
>> but we could not get it to pass more robust testing that the other
>> methods were using.
>>
>> However, LatLonType and GeoHashField are well tested and work well --
>> the Tier type may have better performance when your index is really
>> large, but no active developers understand it and no-one has stepped
>> up to figure it out.
>>
>> ryan
>>
>>
>> On Wed, Nov 3, 2010 at 3:16 PM, Christopher Schmidt
>> <[email protected]> wrote:
>>> Hi all,
>>> I saw a mail thread "Rethinking Cartesian Tiers implementation" (here).
>>> Is there any work in progress regarding this? If yes, is the current
>>> implementation deprecated or do you plan some enhancements (other
>>> projections or spatial indexes) ?
>>> I am asking because I want to use Lucene's spatial indexing in a production
>>> system...
>>>
>>> --
>>> Christopher
>>> twitter: @fakod
>>> blog: http://blog.fakod.eu
>>>
>>
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>
> --
> Christopher
> twitter: @fakod
> blog: http://blog.fakod.eu
>
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--------------------------
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http://www.lucidimagination.com/

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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: [email protected]
WWW:   http://sunset.usc.edu/~mattmann/
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University of Southern California, Los Angeles, CA 90089 USA
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